Increased mortality in ICU patients ≥70 years old with COVID-19 compared to patients with other pneumonias

Background: Patients over 70 years old represent a substantial proportion of the COVID-19 ICU population and their mortality rates are high. The aim of this study is to describe the outcomes of patients ≥70 years old admitted to Dutch ICUs with COVID-19, compared to patients ≥70 years old admitted to the ICU for bacterial and other viral pneumonias, with adjustments for age, comorbidities, severity of illness, and ICU occupancy rate. Methods: Retrospective cohort study including patients ≥70 years old admitted to Dutch ICUs, comparing patients admitted with COVID-19 from March 1st 2020 to January 1st 2022 with patients ≥70 years old admitted because of a bacterial and other viral pneumonia, both divided in a historical (i.e., January 1st 2017 to January 1st 2020) and current cohort (i.e., March 1st 2020 to January 1st 2022). Primary outcome is hospital mortality. Results: 11,525 unique patients ≥70 years old admitted to Dutch ICUs were included; 5094 with COVID-19, 5334 with a bacterial pneumonia, and 1312 with another viral pneumonia. ICU-mortality and in-hospital mortality rates of the patients ≥70 years old admitted with COVID-19 were 39.7% and 47.6% respectively. ICU- and hospital mortality rates of the patients who were admitted in the same or in an historical time period with a bacterial pneumonia or other viral pneumonias were considerably lower (19.5% and 28.6% for patients with a bacterial pneumonia in the historical cohort and 19.1% and 28.8% in the same period, for the patients with other viral pneumonias 20.7% and 28.9%, and 22.7% and 31.8% respectively, all p < 0.001). Differences persisted after correction for several clinical characteristics and ICU occupancy rate. Conclusions: In ICU-patients ≥70 years old, COVID-19 is more severe compared to bacterial or viral pneumonia.